Copy components in an assembly...

According to Sworks help, I can copy components with mates-"Mates between the original components can be preserved inthecopied or mirrored components." I can't seem to get it towork.I've tried highlighted three mated components, CTRL-drag andI'vealso tried Copy and Paste, but they only copy one componentwith nomates. What am I missing, or have I misunderstood thehelp?

TIA
MauriceSolidworksAssemblies